1. Field of the Invention
The present invention relates to a load riving circuit, and in particular, to a driving circuit for a crew protecting device such as an air bag, or suitable for an ABS (Anti-lock Break System) or the like.
2. Description of the Prior Art
In a conventional air bag driving circuit, when a collision condition of a vehicle is detected, a vehicle-mounted battery or back-up condenser supplies ignition current to an igniter (hereinafter, called a squib) so that an air bag will expand.
Such a conventional air bag driving circuit also includes a booster circuit so that the minimum operating voltage of the driving circuit can be secured even if battery wiring is disconnected by collision of the vehicle.
In the booster circuit, however, switching of each circuit element causes noise. To prevent generation of the noise, a protection element such as a filter is provided in the conventional booster circuit.